xref: /linux/tools/testing/selftests/mm/gup_test.c (revision 8804d970fab45726b3c7cd7f240b31122aa94219)
1 #define __SANE_USERSPACE_TYPES__ // Use ll64
2 #include <fcntl.h>
3 #include <errno.h>
4 #include <stdio.h>
5 #include <stdlib.h>
6 #include <unistd.h>
7 #include <dirent.h>
8 #include <sys/ioctl.h>
9 #include <sys/mman.h>
10 #include <sys/stat.h>
11 #include <sys/types.h>
12 #include <pthread.h>
13 #include <assert.h>
14 #include <mm/gup_test.h>
15 #include "../kselftest.h"
16 #include "vm_util.h"
17 
18 #define MB (1UL << 20)
19 
20 /* Just the flags we need, copied from mm.h: */
21 #define FOLL_WRITE	0x01	/* check pte is writable */
22 #define FOLL_TOUCH	0x02	/* mark page accessed */
23 
24 #define GUP_TEST_FILE "/sys/kernel/debug/gup_test"
25 
26 static unsigned long cmd = GUP_FAST_BENCHMARK;
27 static int gup_fd, repeats = 1;
28 static unsigned long size = 128 * MB;
29 /* Serialize prints */
30 static pthread_mutex_t print_mutex = PTHREAD_MUTEX_INITIALIZER;
31 
cmd_to_str(unsigned long cmd)32 static char *cmd_to_str(unsigned long cmd)
33 {
34 	switch (cmd) {
35 	case GUP_FAST_BENCHMARK:
36 		return "GUP_FAST_BENCHMARK";
37 	case PIN_FAST_BENCHMARK:
38 		return "PIN_FAST_BENCHMARK";
39 	case PIN_LONGTERM_BENCHMARK:
40 		return "PIN_LONGTERM_BENCHMARK";
41 	case GUP_BASIC_TEST:
42 		return "GUP_BASIC_TEST";
43 	case PIN_BASIC_TEST:
44 		return "PIN_BASIC_TEST";
45 	case DUMP_USER_PAGES_TEST:
46 		return "DUMP_USER_PAGES_TEST";
47 	}
48 	return "Unknown command";
49 }
50 
gup_thread(void * data)51 void *gup_thread(void *data)
52 {
53 	struct gup_test gup = *(struct gup_test *)data;
54 	int i, status;
55 
56 	/* Only report timing information on the *_BENCHMARK commands: */
57 	if ((cmd == PIN_FAST_BENCHMARK) || (cmd == GUP_FAST_BENCHMARK) ||
58 	     (cmd == PIN_LONGTERM_BENCHMARK)) {
59 		for (i = 0; i < repeats; i++) {
60 			gup.size = size;
61 			status = ioctl(gup_fd, cmd, &gup);
62 			if (status)
63 				break;
64 
65 			pthread_mutex_lock(&print_mutex);
66 			ksft_print_msg("%s: Time: get:%lld put:%lld us",
67 				       cmd_to_str(cmd), gup.get_delta_usec,
68 				       gup.put_delta_usec);
69 			if (gup.size != size)
70 				ksft_print_msg(", truncated (size: %lld)", gup.size);
71 			ksft_print_msg("\n");
72 			pthread_mutex_unlock(&print_mutex);
73 		}
74 	} else {
75 		gup.size = size;
76 		status = ioctl(gup_fd, cmd, &gup);
77 		if (status)
78 			goto return_;
79 
80 		pthread_mutex_lock(&print_mutex);
81 		ksft_print_msg("%s: done\n", cmd_to_str(cmd));
82 		if (gup.size != size)
83 			ksft_print_msg("Truncated (size: %lld)\n", gup.size);
84 		pthread_mutex_unlock(&print_mutex);
85 	}
86 
87 return_:
88 	ksft_test_result(!status, "ioctl status %d\n", status);
89 	return NULL;
90 }
91 
main(int argc,char ** argv)92 int main(int argc, char **argv)
93 {
94 	struct gup_test gup = { 0 };
95 	int filed, i, opt, nr_pages = 1, thp = -1, write = 1, nthreads = 1, ret;
96 	int flags = MAP_PRIVATE, touch = 0;
97 	char *file = "/dev/zero";
98 	pthread_t *tid;
99 	char *p;
100 
101 	while ((opt = getopt(argc, argv, "m:r:n:F:f:abcj:tTLUuwWSHpz")) != -1) {
102 		switch (opt) {
103 		case 'a':
104 			cmd = PIN_FAST_BENCHMARK;
105 			break;
106 		case 'b':
107 			cmd = PIN_BASIC_TEST;
108 			break;
109 		case 'L':
110 			cmd = PIN_LONGTERM_BENCHMARK;
111 			break;
112 		case 'c':
113 			cmd = DUMP_USER_PAGES_TEST;
114 			/*
115 			 * Dump page 0 (index 1). May be overridden later, by
116 			 * user's non-option arguments.
117 			 *
118 			 * .which_pages is zero-based, so that zero can mean "do
119 			 * nothing".
120 			 */
121 			gup.which_pages[0] = 1;
122 			break;
123 		case 'p':
124 			/* works only with DUMP_USER_PAGES_TEST */
125 			gup.test_flags |= GUP_TEST_FLAG_DUMP_PAGES_USE_PIN;
126 			break;
127 		case 'F':
128 			/* strtol, so you can pass flags in hex form */
129 			gup.gup_flags = strtol(optarg, 0, 0);
130 			break;
131 		case 'j':
132 			nthreads = atoi(optarg);
133 			break;
134 		case 'm':
135 			size = atoi(optarg) * MB;
136 			break;
137 		case 'r':
138 			repeats = atoi(optarg);
139 			break;
140 		case 'n':
141 			nr_pages = atoi(optarg);
142 			if (nr_pages < 0)
143 				nr_pages = size / psize();
144 			break;
145 		case 't':
146 			thp = 1;
147 			break;
148 		case 'T':
149 			thp = 0;
150 			break;
151 		case 'U':
152 			cmd = GUP_BASIC_TEST;
153 			break;
154 		case 'u':
155 			cmd = GUP_FAST_BENCHMARK;
156 			break;
157 		case 'w':
158 			write = 1;
159 			break;
160 		case 'W':
161 			write = 0;
162 			break;
163 		case 'f':
164 			file = optarg;
165 			break;
166 		case 'S':
167 			flags &= ~MAP_PRIVATE;
168 			flags |= MAP_SHARED;
169 			break;
170 		case 'H':
171 			flags |= (MAP_HUGETLB | MAP_ANONYMOUS);
172 			break;
173 		case 'z':
174 			/* fault pages in gup, do not fault in userland */
175 			touch = 1;
176 			break;
177 		default:
178 			ksft_exit_fail_msg("Wrong argument\n");
179 		}
180 	}
181 
182 	if (optind < argc) {
183 		int extra_arg_count = 0;
184 		/*
185 		 * For example:
186 		 *
187 		 *   ./gup_test -c 0 1 0x1001
188 		 *
189 		 * ...to dump pages 0, 1, and 4097
190 		 */
191 
192 		while ((optind < argc) &&
193 		       (extra_arg_count < GUP_TEST_MAX_PAGES_TO_DUMP)) {
194 			/*
195 			 * Do the 1-based indexing here, so that the user can
196 			 * use normal 0-based indexing on the command line.
197 			 */
198 			long page_index = strtol(argv[optind], 0, 0) + 1;
199 
200 			gup.which_pages[extra_arg_count] = page_index;
201 			extra_arg_count++;
202 			optind++;
203 		}
204 	}
205 
206 	ksft_print_header();
207 	ksft_set_plan(nthreads);
208 
209 	filed = open(file, O_RDWR|O_CREAT, 0664);
210 	if (filed < 0)
211 		ksft_exit_fail_msg("Unable to open %s: %s\n", file, strerror(errno));
212 
213 	gup.nr_pages_per_call = nr_pages;
214 	if (write)
215 		gup.gup_flags |= FOLL_WRITE;
216 
217 	gup_fd = open(GUP_TEST_FILE, O_RDWR);
218 	if (gup_fd == -1) {
219 		switch (errno) {
220 		case EACCES:
221 			if (getuid())
222 				ksft_print_msg("Please run this test as root\n");
223 			break;
224 		case ENOENT:
225 			if (opendir("/sys/kernel/debug") == NULL)
226 				ksft_print_msg("mount debugfs at /sys/kernel/debug\n");
227 			ksft_print_msg("check if CONFIG_GUP_TEST is enabled in kernel config\n");
228 			break;
229 		default:
230 			ksft_print_msg("failed to open %s: %s\n", GUP_TEST_FILE, strerror(errno));
231 			break;
232 		}
233 		ksft_test_result_skip("Please run this test as root\n");
234 		ksft_exit_pass();
235 	}
236 
237 	p = mmap(NULL, size, PROT_READ | PROT_WRITE, flags, filed, 0);
238 	if (p == MAP_FAILED)
239 		ksft_exit_fail_msg("mmap: %s\n", strerror(errno));
240 	gup.addr = (unsigned long)p;
241 
242 	if (thp == 1)
243 		madvise(p, size, MADV_HUGEPAGE);
244 	else if (thp == 0)
245 		madvise(p, size, MADV_NOHUGEPAGE);
246 
247 	/*
248 	 * FOLL_TOUCH, in gup_test, is used as an either/or case: either
249 	 * fault pages in from the kernel via FOLL_TOUCH, or fault them
250 	 * in here, from user space. This allows comparison of performance
251 	 * between those two cases.
252 	 */
253 	if (touch) {
254 		gup.gup_flags |= FOLL_TOUCH;
255 	} else {
256 		for (; (unsigned long)p < gup.addr + size; p += psize())
257 			p[0] = 0;
258 	}
259 
260 	tid = malloc(sizeof(pthread_t) * nthreads);
261 	assert(tid);
262 	for (i = 0; i < nthreads; i++) {
263 		ret = pthread_create(&tid[i], NULL, gup_thread, &gup);
264 		assert(ret == 0);
265 	}
266 	for (i = 0; i < nthreads; i++) {
267 		ret = pthread_join(tid[i], NULL);
268 		assert(ret == 0);
269 	}
270 
271 	free(tid);
272 
273 	ksft_exit_pass();
274 }
275